Tuesday, January 26, 2016

Is Global Warming Behind The Record Snowfall Of Winter Storm Jonas?


Two days ago on RealClimate a post entitled "Blizzard Jonas and the Slowdown of the Gulf Stream System" suggests that there might be a link.  The argument is that rising ocean surface temperatures in the North Atlantic, especially somewhat south of Greenland, are tied to a slowing of the Gulf Stream.  These higher temperatures off the US East Coast then may be a clause of larger snowfalls in storms in the eaastern US, with a possible direct influence on this coming from warmer fresh water coming off Greenland  with glacier melt.  If this continues there could also be substantial impacts on northwestern Europe, although these may include cooling in some places.  This is tentative, but certainly something that should taken seriously and further studied.

Let me compare this with a possibly related phenomenon, which provides a warning that we must  proceed cautiously with this.  I am referring to the widespread reports about a decade ago claiming that global warming was increasing the frequency of hurricane in North America.  Quite a few public figures made a great big fuss over this, including Al Gore.  However, it turns out that the effect is a very complicated mixed bag, and if  anything it is the other way around, warming temperatures may lead to a lower frrequency  of Atlantic hurricanes?  How can this be?  One possibility is higher temperatures bring more sandstorms in western Africa that blow over the Atlantic, with this greater sand in the air inhibiting the formation of tropical depressions that lead to hurricanes.

While that may be the case, there is stronger evidence, although this remains a matter of  serious debate among climatologists, about the intensity of hurricanes that do occur, and such storms as Katrina and Sandy (which hit the New Jersey shoreline with flooding as Winter Storm Jonas has) being poster children for  this.  The argument on this is really straightforward: intensity of hurricanes does seem to be tied to higher late summer sea surface temperatures in the Atlantic and the Gulf of Mexico.  So, the case for more intense hurricanes to occur even as there may be fewer hurricanes overall is serious, if not  universally accepted by climatologists, and the mechanism would have similarities to the phenomenon now being posed as possibly increasing snowfall amounts in the eastern US due to  warmer ocean surface temperatures in the Atlantic.

Barkley Rosser


Myrtle Blackwood said...

See: Graph showing the number of worldwide extreme climate-related events (including heat waves, cold spells, windstorms, extreme precipitation, and drought) and associated damage costs for the period 1950 - 1999
Extreme climatic events and their evolution under changing climatic conditions
Martin Benistona,*, David B. Stephensonb
a Department of Geosciences, University of Fribourg, Perolles, Fribourg CH-1700, Switzerland
b Department of Meteorology, University of Reading, United Kingdom
Received 3 September 2003; accepted 28 June 2004
Global and Planetary Change 44 (2004) 1 – 9
Available online at www.sciencedirect.com

Myrtle Blackwood said...

Now out of date observations as described in 'Global Warming - the complete briefing, third edition' by John Houghton. Updated in 2004

1987, October 16th - the worst storm experienced in Western Europe since 1703. (Over 15 million trees were blown down in South East England and the London area). However storm force winds imilar or even greater intensity (and covering a greater area in Western Europe) have struck since. 4 times in 1990 and 3 times in 1999. There's been a 10-fold increase in economic losses by storms etc. between the 1950s and 1990s. Notable examples of floods in the 2 decades prior to 2004.

Unknown said...

Barkley I know as much about climate change as I do about Russia. Which is to say vanishingly close to nothing. But happy to see you here teaching me stuff. Good times again.

Though I am sure Michael Mann is wrong. Because Putin invented hockey sticks. Or did I get that wrong too?

Myrtle Blackwood said...

Some further references (very recent):

Research Letter
What would happen to Superstorm Sandy under the influence of a substantially warmer Atlantic Ocean?
William K. M. Lau,
J. J. Shi,
W. K. Tao,
K. M. Kim
First published: 19 January 2016Full publication history
DOI: 10.1002/2015GL067050View/save citation
Cited by: 0 articles Check for new citations
Robert Scribbler on 31st December 2015:
“we are now starting to tease out a few of the direct influences of climate change on extreme weather events. One particularly powerful element being what is known as the heat-moisture engine. It’s well known that temperature differentials and rates of evaporation can have a significant influence on weather. And climate change itself fundamentally alters these aspects of weather by 1 — changing the rate of evaporation and precipitation on a global basis and 2 — putting hot and cold air and water masses in places where they’ve never been before. …Another feature in the North Atlantic related to climate change is a cool pool of water south of Greenland. This pool is generated by increasing glacial melt outflows from the warming and thawing mountains of ice covering that frozen isle. In juxtaposition to the warming Barents, this cool pool creates what in weather terms is called a dipole. A region of cold facing off against a region of hot. Dipoles are notorious for their potential to generate extreme weather. And the Barents/North Atlantic anomaly dipole is something entirely new. A weather system that aims a more heavily moisture laden Atlantic storm track directly at the United Kingdom. An island nation that this year is sitting directly in the path of a northward moving warm wind. A warm air and moisture flow that has all too frequently embedded monster rainstorms never before seen in the isles’ history….”

Amidst Disasters Around the World, Top Scientists Declare Links Between Extreme Weather and Climate Change. ROBERT SCRIBBLER. 31st December 2015